A surprising new picture of ocean circulation could have major consequences for climate science, Some experts say the Atlantic Ocean circulation is already slowing down — but we’re just beginning to learn how it really works, WP By Chris Mooney, January 31 2019

It may be the biggest wild card in the climate system. Scientists have long feared that the so-called “overturning” circulation in the Atlantic Ocean could slow down or even halt due to climate change — a change that would have enormous planetary consequences.

But at the same time, researchers have a limited understanding of how the circulation actually works, since taking measurements of its vast and remote currents is exceedingly difficult. And now, a major new research endeavor aimed at doing just that has suggested a dramatic revision of our understanding of the circulation itself.

A new 21-month series of observations in the frigid waters off Greenland has led to the discovery that most of the overturning — in which water not only sinks but returns southward again in the ocean depths — occurs to the east, rather than to the west, of the enormous ice island. If that’s correct, then climate models that suggest the circulation will slow as the climate warms may have to be revised to take this into account.

……….. The new results come from the $ 32 million OSNAP, or “Overturning in the Subpolar North Atlantic,” program, the first attempt to comprehensively measure the circulation in the exceedingly remote regions in question. These icy seas, it is believed, are where cold, salty waters — which are extremely dense — sink below the sea surface into the depths, and then travel back southward again all the way to the Southern Hemisphere.

This “overturning” process is crucial because the sinking in the North Atlantic effectively pulls more warm, salty water northward via a system of currents that includes the Gulf Stream. This heat delivery, in turn, shapes climate throughout much of the region, and especially in Europe.

Better understanding of how the circulation works is key, since some scientists have already proposed that it is slowing down, with major consequences, including ocean warming and sea level rise off the U.S. east coast.

Global temperature maps in recent years have shown a strange area of anomalously cold temperatures in the ocean to the southeast of Greenland, along with very warm temperatures off the coast of New England.

The cold region — which has been dubbed the “cold blob” and also “warming hole” — is strikingly anomalous at a time when the Earth and its oceans are otherwise warming. And the suggestion has been that this represents a decline in the volume of heat being transported northward by the circulation.

Greenland ice melting four times faster than in 2003, study finds, Southwest part of the island could be major contributor to sea level rise, EurekAlert, 21 Jan 19, OHIO STATE UNIVERSITY COLUMBUS, Ohio – Greenland is melting faster than scientists previously thought–and will likely lead to faster sea level rise–thanks to the continued, accelerating warming of the Earth’s atmosphere, a new study has found.

Scientists concerned about sea level rise have long focused on Greenland’s southeast and northwest regions, where large glaciers stream iceberg-sized chunks of ice into the Atlantic Ocean. Those chunks float away, eventually melting. But a new study published Jan. 21 in the Proceedings of the National Academy of Sciences found that the largest sustained ice loss from early 2003 to mid-2013 came from Greenland’s southwest region, which is mostly devoid of large glaciers.

“Whatever this was, it couldn’t be explained by glaciers, because there aren’t many there,” said Michael Bevis, lead author of the paper, Ohio Eminent Scholar and a professor of geodynamics at The Ohio State University. “It had to be the surface mass–the ice was melting inland from the coastline.”

That melting, which Bevis and his co-authors believe is largely caused by global warming, means that in the southwestern part of Greenland, growing rivers of water are streaming into the ocean during summer. The key finding from their study: Southwest Greenland, which previously had not been considered a serious threat, will likely become a major future contributor to sea level rise………https://www.eurekalert.org/pub_releases/2019-01/osu-gim011419.php

Technology meant to help solve the world’s growing water shortage is producing a salty environmental dilemma.

Desalination facilities, which extract drinkable water from the ocean, discharge around 142 billion liters of extremely salty water called brine back into the environment every day, a study finds. That waste product of the desalination process can kill marine life and detrimentally alter the planet’s oceans, researchers report January 14 in Science of the Total Environment.

“On the one hand, we are trying to provide populations — particularly in dry areas — with the needed amount of good quality water. But at the same time, we are also adding an environmental concern to the process,” says study coauthor Manzoor Qadir, an environmental scientist at the United Nations University Institute for Water, Environment and Health in Hamilton, Canada.

Between human population growth and climate change, water is becoming increasingly scarce (SN: 8/18/18, p. 14). Desalination technology has become a viable solution to this problem and has grown exponentially in popularity since the 1980s. Almost 16,000 plants now operate worldwide.

Desalination relies on evaporation or specialized membranes to either chemically or electrically separate pure water from a stream of saltwater. But two streams always flow out of the system: one that becomes water that people can use, and another with the leftover, extra-salty brine, which is released back into the environment.

Previous evaluations didn’t assess how much brine these facilities produced, Qadir says. Scientists assumed that desalination facilities on average equally produced brine and pure water — one liter of brine for every liter of pure water. That turned out to be wrong.

Using data on the water sources and technology used at desalination facilities around the globe, Qadir and his colleagues estimated for the first time how much brine is discharged daily. For every liter of pure water made, they found that on average 1.5 liters of highly concentrated brine is released back into the environment. Per day, that value translates to more than half the daily volume of water pouring over Niagara Falls, with 70 percent of it originating from desalination plants in arid North Africa and the Middle East.

As brine re-enters the ocean, “it creates a kind of local environment,” Qadir says. The highly concentrated discharge, which can also contain metals and antifouling chemicals, is denser than seawater, so it flows as a salty plume to the seafloor and can poison marine organisms living nearby. Some brine can also still be hot from evaporative processes during desalination. Because hot water doesn’t hold oxygen as well as cold water, ocean areas where brine enters can become depleted of oxygen.

An international standard requiring wastewater treatment and the use of environmentally friendly chemicals in desalination discharge does exist, says Yoram Cohen, a chemical engineer at UCLA. “But whether all people follow it, I don’t know.”

Save for some scientific studies, not much is being done to resolve the issue, Qadir says. “At the government level, I don’t see that there is a serious attempt that has been made.”

Suggestions have been proposed for repurposing the brine, including for watering salt-tolerant agricultural fields, extracting metals such as magnesium or uranium, or harvesting salt versus mining for it. In terms of technology, you can take the brine “and evaporate it to recover the salt,” Cohen says. “But the price is huge.”

Depending on location and type of technology, desalination alone can cost between $0.50 and over $2 to produce 1,000 liters of drinkable water — about what two people in the United States use in a day. Further evaporating the brine waste only increases the cost.

Modern desalination technologies, such as graphene oxides, are becoming more cost effective and releasing less brine discharge (SN: 8/20/16, p. 22). But they are not universally distributed and are uncommon in the Middle East where desalination is most used. “We need to make sure that with our efforts, we are able to use more of those types of technology which produce more desalinated water than brine,” Qadir says.

Explainer: Why sea levels aren’t rising at the same rate globally, A spinning planet, melting ice sheets and warmer waters all contribute to sea level rise, Science news for Students, KATY DAIGLE, CAROLYN GRAMLING, JAN 10, 2019 The sea is coming for the land. In the 20th century, ocean levels rose by a global average of about 14 centimeters (some 5.5 inches). Most of that came from warming water and melting ice. But the water didn’t rise the same amount everywhere. Some coastal areas saw more sea level rise than others. Here’s why:

Swelling seawater As water heats up, its molecules spread out. That means warmer water takes up slightly more space. It’s just a tiny bit per water molecule. But over an ocean, it’s enough to bump up global sea levels……..

Land a-rising Heavy ice sheets — glaciers — covered much of the Northern Hemisphere about 20,000 years ago. The weight of all that ice compressed the land beneath it in areas such as the northeastern United States. Now that this ice is gone, the land has been slowly rebounding to its former height. So in those areas, because the land is rising, sea levels appear to be rising more slowly.

But regions that once lay at the edges of the ice sheets are sinking. ……..

Land a-falling, Earthquakes can make land levels rise and fall…….

Glaciers begone Melting glaciers also can add water to the oceans. But these huge ice slabs affect sea levels in other ways, too.

https://www.eurekalert.org/pub_releases/2019-01/hjap-hcp010419.php– 4 Jan 19, Whereas most of the ocean is responding to modern warming, the deep Pacific may be cooling, HARVARD JOHN A. PAULSON SCHOOL OF ENGINEERING AND APPLIED SCIENCES The ocean has a long memory. When the water in today’s deep Pacific Ocean last saw sunlight, Charlemagne was the Holy Roman Emperor, the Song Dynasty ruled China and Oxford University had just held its very first class. During that time, between the 9th and 12th centuries, the earth’s climate was generally warmer before the cold of the Little Ice Age settled in around the 16th century. Now, ocean surface temperatures are back on the rise but the question is, do the deepest parts of the ocean know that?

Researchers from the Woods Hole Oceanographic Institution and Harvard University have found that the deep Pacific Ocean lags a few centuries behind in terms of temperature and is still adjusting to the advent of the Little Ice Age. Whereas most of the ocean is responding to modern warming, the deep Pacific may be cooling.

The research is published in Science.

“Climate varies across all timescales,” said Peter Huybers, Professor of Earth and Planetary Sciences in the Department of Earth and Planetary Sciences and of Environmental Science and Engineering at the Harvard John A. Paulson School of Engineering and Applied Sciences and co-author of the paper. “Some regional warming and cooling patterns, like the Little Ice Age and the Medieval Warm Period, are well known. Our goal was to develop a model of how the interior properties of the ocean respond to changes in surface climate.”

What that model showed was surprising.

“If the surface ocean was generally cooling for the better part of the last millennium, those parts of the ocean most isolated from modern warming may still be cooling,” said Jake Gebbie, a physical oceanographer at Woods Hole Oceanographic Institution and lead author of the study.

The model is a simplification of the actual ocean. To test the prediction, Gebbie and Huybers compared the cooling trend found in the model to ocean temperature measurements taken by scientists aboard the HMS Challenger in the 1870s and modern observations from the World Ocean Circulation Experiment of the 1990s.

The HMS Challenger, a three-masted wooden sailing ship originally designed as a British warship, was used for the first modern scientific expedition to explore the world’s ocean and seafloor. During the expedition from 1872 to 1876, thermometers were lowered into the ocean depths and more than 5,000 temperature measurements were logged.

“We screened this historical data for outliers and considered a variety of corrections associated with pressure effects on the thermometer and stretching of the hemp rope used for lowering thermometers,” said Huybers.

The researchers then compared the HMS Challenger data to the modern observations and found warming in most parts of the global ocean, as would be expected due to the warming planet over the 20th Century, but cooling in the deep Pacific at a depth of around two kilometers depth.

“The close correspondence between the predictions and observed trends gave us confidence that this is a real phenomenon,” said Gebbie.

These findings imply that variations in surface climate that predate the onset of modern warming still influence how much the climate is heating up today. Previous estimates of how much heat the Earth had absorbed during the last century assumed an ocean that started out in equilibrium at the beginning of the Industrial Revolution. But Gebbie and Huybers estimate that the deep Pacific cooling trend leads to a downward revision of heat absorbed over the 20th century by about 30 percent.

“Part of the heat needed to bring the ocean into equilibrium with an atmosphere having more greenhouse gases was apparently already present in the deep Pacific,” said Huybers. “These findings increase the impetus for understanding the causes of the Medieval Warm Period and Little Ice Age as a way for better understanding modern warming trends.”

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This research was funded by the James E. and Barbara V. Moltz Fellowship and National Science Foundation grants OCE-1357121 and OCE-1558939

A new scientific survey has found that the glaciers of the Arctic are the world’s biggest contributors to rising seas, shedding ice at an accelerating rate that now adds well over a millimeter to the level of the ocean every year.

That is considerably more ice melt than Antarctica is contributing, even though the Antarctic contains far more ice. Still, driven by glacier clusters in Alaska, Canada and Russia and the vast ice sheet of Greenland, the fast-warming Arctic is outstripping the entire ice continent to the south — for now.

However, the biggest problem is that both ice regions appear to be accelerating their losses simultaneously — suggesting that we could be in for an even faster rate of sea-level rise in future decades. Seas are rising by about three millimeters each year, according to NASA. That’s mainly driven by the Arctic contribution, the Antarctic and a third major factor — that ocean water naturally expands as it warms.

For Arctic ice loss, “the rate has tripled since 1986,” said Jason Box, first author of the new study and a scientist at the Geological Survey of Denmark and Greenland. “So it clearly shows an acceleration of the sea-level contribution.”

“Antarctica will probably take over at some point in the future, but during the past 47 years of this study, it’s not controversial that the Arctic is the largest contribution of land ice to sea-level rise,” he said.

Scientists in the United States, Chile, Canada, Norway and the Netherlands contributed to the work, published in Environmental Research Letters.

The Arctic is also losing floating sea ice at a rapid pace, but that loss does not contribute substantially to rising seas (though it has many other consequences). Sea ice losses closely match what is happening on land, which makes sense because both phenomena are being driven by the fast warming of the atmosphere in the Arctic, which has heated up at a rate much faster than seen in lower latitudes. Warming seas are also driving some of the ice loss.

Here’s the new study’s tally of where all the Arctic ice loss has come from since 1971: [diagram on original]

The total Arctic loss at present is 447 billion tons of ice per year — which Box calculated is about 14,000 tons of water per second. That’s for the period between 2005 and 2015. Between 1986 and 2005, the loss is calculated at around 5,000 tons per second — therefore, the rate has almost tripled.

Separate research has recently found that the Antarctic’s loss rate has also tripled in just a decade, reaching 219 billion tons per year from 2012 to 2017.

Assuming these numbers are correct and summing them together, the world’s polar regions are losing about 666 billion tons of ice to the ocean each year — amounting to a little bit less than two millimeters of sea-level rise annually.

Treating the Arctic as a whole can miss something, though, notes Christopher Larsen, a glacier expert at the University of Alaska at Fairbanks.

Namely, the Arctic acceleration documented in the study is really being driven by Greenland, which contains more than 20 feet of potential sea-level rise, dwarfing all other Arctic ice sources.

“With respect to the present rate of ice mass loss, and the increasing rates thereof, it is Greenland that has the most significant rate of increased mass loss in the present day,” Larsen said in an email.

“This is especially noteworthy as ultimately Greenland has the most ice to lose in the Northern Hemisphere,” he said. “As rapid as ice loss is now or may become anywhere in the north, the regional totals of ice mass within Alaska or the Arctic Canada are smaller than what Greenland holds.”

To give a sense of the scale of the Arctic losses, Box imagined what it would mean if they were distributed among Earth’s human population.

“If you take the 7.7 billion people on Earth and divide the present-day numbers, from 2005 to 2015, each person on Earth would have the equivalent of 160 liters per day, every day, every year,” Box said.

Sep 3, 2018 Ian Harvey In July of 2018, Andrew Thaler wrote for Southern Fried Science that there were at least two nuclear capsules, four unarmed weapons, and one armed nuclear weapon sitting on the ocean floor, that he was aware of.

His information was based on declassified U.S. Department of Defense narrative summaries of accidents involving U.S. nuclear weapons.

He noted that the documents he had access to only covered the period of time between 1950 and 1980. Any more recent data would still be classified. There is reason to believe that his estimated numbers for nuclear material in the oceans are far too low.

Business Insider in 2013 wrote that since 1950 there have been 32 nuclear weapon accidents, known as Broken Arrows, where an unexpected event involving nuclear weapons resulted in the firing, launching, theft, or loss of said weapon.

BI reported in this piece that there were six nuclear weapons that have been lost and never recovered. The time frames for the BI list continued into the 2000’s, but this is also a lowball number.

According to a 1989 article in the New York Times, however, there have been at least 50 nuclear warheads and nine reactors scattered on the ocean floors since 1956.

These were the result of various accidents on the part of U.S. and Soviet bombers, ships, and rockets, according to a study of naval accidents that was published by Greenpeace and the Institute for Policy Studies.

The study outlines 1,276 accidents, both nuclear and non-nuclear, on the part of the world’s navies, and has some, more limited, information on another 1,000 accidents. The study points out that the total number of incidents amounts to one major peacetime accident a week

Information for the study was gathered mostly through the Freedom of Information Act, which included American intelligence assessments of Soviet naval accidents.

Eighty days after it fell into the ocean following the January 1966 midair collision between a nuclear-armed B-52G bomber and a KC-135 refueling tanker over Palomares, Spain, this B28RI nuclear bomb was recovered from 2,850 feet (869 meters) of water and lifted aboard the USS Petrel (note the missing tail fins and badly dented “false nose”).

The authors also received information from the governments of other nations. The report said that the worst accident occurred in 1986, when a Soviet submarine sank 600 miles northeast of the Bermuda coast, depositing two nuclear reactors and 32 nuclear warheads on the bottom of the ocean.

That one accident left more nuclear material under the sea than the authors of the first two pieces posited, combined. The study also notes that it doesn’t reflect data on any of the “many hundreds” of Soviet accidents about which little is known, and suggested that the Soviet Navy has far more accidents than those of America.

The accidents are, for the most part, due to human factors, ranging from issues of faulty navigation to outright sabotage.

So far, the U.S. has admitted to knowing of one hydrogen bomb that is leaking radioactive material. That bomb was accidentally dropped into the sea south of Japan in 1965 by an aircraft carrier.

There is some likelihood that other bombs may have also begun to leak radiation into the water, and are just unknown as yet. Even if it hasn’t happened yet, the chances of such leaks will increase over time as the weapons degrade, having the potential to cause untold harm to the oceans and our planet as a whole.

Portrait of a planet on the verge of climate catastropheAs the UN sits down for its annual climate conference this week, many experts believe we have passed the point of no return, Guardian, byRobin McKie, 2 Dec 18 “…………Great Barrier Reef Coral reefs cover a mere 0.1% of the world’s ocean floor but they support about 25% of all marine species. They also provide nature with some of its most beautiful vistas. For good measure, coral reefs protect shorelines from storms, support the livelihoods of 500 million people and help generate almost £25bn of income. Permitting their destruction would put the planet in trouble – which is precisely what humanity is doing.

Rising sea temperatures are already causing irreparable bleaching of reefs, while rising sea levels threaten to engulf reefs at a faster rate than they can grow upwards. Few scientists believe coral reefs – which are made of simple invertebrates related to sea anemones – can survive for more than a few decades.

Yet those who have sounded clear warnings about our reefs have received little reward. Professor Terry Hughes, a coral expert at James Cook University in Queensland, Australia, recently studied the impact of El Niño warmings in 2016 and 2017 on Australia’s Great Barrier Reef, the world’s largest coral reef and its largest living entity – and wept when he saw the damage.

“The 2016 event killed 30% of corals, the one a year later killed another 20%. Very close to half the corals have died in the past three years,” he said recently.

For his pains, Hughes has faced demands from tourist firms for his funding to be halted because he was ruining their business. “The Australian government is still promoting new developments of coal mines and fracking for gas,” Hughes said, after being named joint recipient of the John Maddox prize, given to those who champion science in the face of hostility and legal threats. “If we want to save the Great Barrier Reef, these outdated ambitions need to be abandoned. Yet Australia’s greenhouse gas emissions are rising, not falling. It’s a national disgrace.”

Oceans Are Warming Up Much Faster Than Previously Thought https://e360.yale.edu/digest/oceans-are-warming-up-much-faster-than-previously-thoughtThe world’s oceans have soaked up much more excess heat in recent decades than scientists previously thought — as much as 60 percent more, according to anew study published in the journal Nature. The new research suggests the global could warm even faster in the coming decades than researchers originally predicted, The Washington Post reported.The researchers, led by geoscientist Laure Resplandy of Princeton University, found that oceans absorbed 13 zettajoules — a joule, the standard unit of energy, followed by 21 zeroes — of heat energy each year between 1991 and 2016. Based on these findings, they argue, nations must reduce their greenhouse gas emissions 25 percent more than previously estimated if they hope to keep global warming below 2 degrees Celsius.“Imagine if the ocean was only 30 feet deep,” Resplandy said in a statement. “Our data show that it would have warmed by 6.5 degrees C [11.7 degrees Fahrenheit] every decade since 1991. In comparison, the estimate of the last IPCC assessment report would correspond to a warming of only 4 degrees C [7.2 degrees F] every decade.”

Scientists have long struggled to quantify ocean warming before 2007 — the year that a network of robotic sensors known as Argo were deployed into the world’s oceans to track things like temperature and salinity. For pre-2007 data, the new research examined the volume of oxygen and carbon dioxide released from the oceans as they heated up, providing scientists an indicator for ocean temperature change.

“We thought that we got away with not a lot of warming in both the ocean and the atmosphere for the amount of CO2 that we emitted,” Resplandy told The Washington Post. “But we were wrong. The planet warmed more than we thought. It was hidden from us just because we didn’t sample it right. But it was there. It was in the ocean already.”

Fukushima water release into sea faces chorus of opposition https://mail.google.com/mail/u/0/#inbox?compose=DmwnWtDqNzxklZTsLVvsRFtgBQZHzxshPgMCgrVGpNqZnjrqDwNNWbPprDwxPlNFzCVZnfDvsQwVCitizens and environmental groups have expressed opposition to the idea of releasing into the ocean water tainted with tritium, a radioactive substance, from Tokyo Electric Power Company Holdings Inc.’s disaster-stricken Fukushima No. 1 nuclear power plant.“Long-term storage (of the tritium-containing water) is possible from technical and economic standpoints,” Komei Hosokawa, 63, an official of the Citizens’ Commission on Nuclear Energy, said at a public hearing held in Tokyo on Friday by a subcommittee of the Agency for Natural Resources and Energy. “The radiation levels in the water will decrease during the long-term storage,” he added.

At a similar hearing held the same day in Koriyama, Fukushima Prefecture, Aki Hashimoto, a housewife from the city, said, “I never want to see further worsening of ocean pollution from radiation.”

Opinions objecting to the release of the tritium-contaminated water into the ocean were also heard at a hearing held in the Fukushima town of Tomioka on Thursday.

After Friday’s hearings, Ichiro Yamamoto, who heads the subcommittee, told reporters that many participants in the hearings said the tainted water should continue to be held in storage tanks.

The subcommittee will study the option of keeping the water in the tanks, he added.

Tepco is lowering the radiation levels in contaminated water at the Fukushima No. 1 plant using special equipment, but the device cannot remove tritium.

The tritium-tainted water is stored in tanks within the premises of the power plant, which was heavily damaged in the March 2011 earthquake and tsunami.

In 2016, an expert panel of the Agency for Natural Resources and Energy discussed five methods to dispose of the tritium-tainted water —injection deep into the ground, release into the sea after dilution, release into the air through evaporation, conversion into hydrogen through electrolysis, and burying it after it is solidified.

The panel estimated that the ocean release is the cheapest option, costing up to about ¥3.4 billion.

TAIPEI, TAIWAN — Floating Chinese nuclear power plants stationed in the South China Sea would help Beijing fortify its claims in a decades-old maritime sovereignty dispute, but come with environmental risks, scholars say.

China plans to power some of its claimed islets with nuclear energy, the U.S. Department of Defense recently told Congress in an annual report on Chinese military activities. Beijing had indicated last year it was planning to install “floating nuclear power stations” that would start operating before 2020, the report says.

That development would bulk up China’s maritime claim after about a decade of land reclamation in parts of the 3.5 million-square-kilometer sea and the sending of military units to some of the artificial islands, analysts say. Rival maritime claimants Brunei, Malaysia, the Philippines, Taiwan and Vietnam lack similar means to electrify their holdings.

“You are literally facilitating increase of physical control of the South China Sea,” said Collin Koh, maritime security research fellow at Nanyang Technological University in Singapore.

“I think the more immediate concerns of anyone, be they claimants, be they non-claimants, is a huge ecological risk, and taking into account that Chinese nuclear energy technology may not necessarily be one of the best in the world,” he said………

Ecological risks

China is unlikely to do an environmental impact study on any nuclear-power barges before installing them, Koh said. A “runaway reactor” could lead to a “major ecological disaster,” he said. The U.S. Defense Department report notes that the sea is prone to typhoons, during which most vessels seek shelter.

Pirates and terrorists at sea could also disrupt a nuclear power barge, said Andrew Yang, secretary-general of the Chinese Council of Advanced Policy Studies think tank.

As sea levels rise due to climate change, so do the global hazards and potential devastating damages from tsunamis, according to a new study by a partnership that included Virginia Tech.

Even minor sea-level rise, by as much as a foot, poses greater risks of tsunamis for coastal communities worldwide.

The threat of rising sea levels to coastal cities and communities throughout the world is well known, but new findings show the likely increase of flooding farther inland from tsunamis following earthquakes. Think of the tsunami that devasted a portion of northern Japan after the 2011 Tohoku-Oki earthquake, causing a nuclear plant to melt down and spread radioactive contamination.

These findings are at the center of a new Science Advances study, headed by a multi-university team of scientists from the Earth Observatory of Singapore, the Asian School of the Environment at Nanyang Technological University, and National Taiwan University, with critical support from Virginia Tech’s Robert Weiss, an associate professor in the Department of Geosciences, part of the College of Science.

“Our research shows that sea-level rise can significantly increase the tsunami hazard, which means that smaller tsunamis in the future can have the same adverse impacts as big tsunamis would today,” Weiss said, adding that smaller tsunamis generated by earthquakes with smaller magnitudes occur frequently and regularly around the world. For the study, Weiss was critical in helping create computational models and data analytics frameworks.

At Virginia Tech, Weiss serves as director of the National Science Foundation-funded Disaster Resilience and Risk Management graduate education program and is co-lead of Coastal@VT, comprised of 45 Virginia Tech faculty from 13 departments focusing on contemporary and emerging coastal zone issues, such as disaster resilience, migration, sensitive ecosystems, hazard assessment, and natural infrastructure.

For the study, Weiss and his partners, including Lin Lin Li, a senior research fellow, and Adam Switzer, an associate professor, at the Earth Observatory of Singapore, created computer-simulated tsunamis at current sea level and with sea-level increases of 1.5 feet and 3 feet in the Chinese territory of Macau. Macau is a densely populated coastal region located in South China that is generally safe from current tsunami risks.

At current sea level, an earthquake would need to tip past a magnitude of 8.8 to cause widespread tsunami inundation in Macau. But with the simulated sea-level rises, the results surprised the team.

The sea-level rise dramatically increased the frequency of tsunami-induced flooding by 1.2 to 2.4 times for the 1.5-foot increase and from 1.5 to 4.7 times for the 3-foot increase. “We found that the increased inundation frequency was contributed by earthquakes of smaller magnitudes, which posed no threat at current sea level, but could cause significant inundation at higher sea-level conditions,” Li said.

n the simulated study of Macau – population 613,000 – Switzer said, “We produced a series of tsunami inundation maps for Macau using more than 5,000 tsunami simulations generated from synthetic earthquakes prepared for the Manila Trench.” It is estimated that sea levels in the Macau region will increase by 1.5 feet by 2060 and 3 feet by 2100, according to the team of U.S.-Chinese scientists.

The hazard of large tsunamis in the South China Sea region primarily comes from the Manila Trench, a megathrust system that stretches from offshore Luzon in the Philippines to southern Taiwan. The Manila Trench megathrust has not experienced an earthquake larger than a magnitude 7.8 since the 1560s. Yet, study co-author Wang Yu, from the National Taiwan University, cautioned that the region shares many of the characteristics of the source areas that resulted in the 2004 Sumatra-Andaman earthquake, as well as the 2011 earthquake in northern Japan, both causing massive loss of life.

These increased dangers from tsunamis build on already known difficulties facing coastal communities worldwide: The gradual loss of land directly near coasts and increased chances of flooding even during high tides, as sea levels increase as the Earth warms.

“The South China Sea is an excellent starting point for such a study because it is an ocean with rapid sea-level rise and also the location of many mega cities with significant worldwide consequences if impacted. The study is the first if its kind on the level of detail, and many will follow our example,” Weiss said.

Policymakers, town planners, emergency services, and insurance firms must work together to create or insure safer coastlines, Weiss added.

“Sea-level rise needs to be taken into account for planning purposes, for example for reclamation efforts but also for designing protective measures, such as seawalls or green infrastructure.”

He added, “What we assumed to be the absolute worst case a few years ago now appears to be modest for what is predicted in some locations. We need to study local sea-level change more comprehensively in order to create better predictive models that help to make investments in infrastructure that are or near sustainable.”

One of the more serious impacts of human-caused climate disruption occurs when seawater absorbs excess carbon dioxide from the atmosphere. When this occurs, the carbon dioxide reacts with the water to form carbonic acid, which then ultimately reduces its pH level. For much of the marine life in the oceans, the consequences of this will be dire.

“Animals that have a calcium carbonate shell such as, corals, coralline algae, pteropods, bivalves and gastropods are negatively affected by ocean acidification,” said Richard Feely, a senior scientist with the National Oceanic and Atmospheric Administration’s (NOAA) Pacific Marine Environmental Laboratory. “In some cases, their shells are weakened or actually dissolve while the animal is still alive. Fish behavior is also impacted by ocean acidification such that some species lose their ability to navigate or avoid predators.”………

As oceans absorb increasing amounts of our industrial emissions of CO2, their pH is expected to drop to a staggering 7.7 pH by 2100, according to professor of marine chemistry Aleck Wang at the Woods Hole Oceanographic Institution. Wang told National Geographic that by 2100, “you are going to start seeing calcium carbonate shells dissolve. It’s not going to be that far away.”

Most scientists studying the impacts of ocean acidification agree that by killing off the types of organisms Feely mentioned (corals, oysters, types of phytoplankton, etc.), major portions of the oceanic food chain could be greatly impacted.

Feely told Truthout that key marine organisms and ecosystem services face contrasting risks from the combined effects of ocean acidification, warming and sea level rise, and that even under the most stringently controlled CO2 emissions scenario, warm water corals and mid-latitude bivalves “are considered to be at high risk by 2100.”

“Under our current rate of CO2 emissions, most marine organisms are expected to have very high risk of impacts by 2100 and many by 2050,” Feely said. “These results are consistent with evidence of biological responses during high-CO2 periods in the geological past. Impacts to the ocean’s ecosystem services follow a parallel trajectory.”

……… According to Feely, high latitude and upwelling regions of the oceans are already “seriously affected by ocean acidification,” and he said that he and his colleagues are “already observing dissolution of pteropod shells in the Arctic and Southern Oceans, and also upwelling regions along the West Coast of North America.”

………Feely’s deepest concerns about ocean acidification are that so many ecosystem processes that humans depend on for food and survival are already impacted by both oceanic warming and acidification, and the risks of these impacts to these services only increases with continued CO2 emissions, which currently show little signs of slowing down.

“[The impacts] are predicted to remain moderate for the next several decades for most services under stringent emission reductions,” Feely said. “But the business-as-usual scenario would put all ecosystem services at high or very high risk over the same time frame.”

A 2015 study warned that ocean acidification could cause dramatic changes to phytoplankton, the basis of the entire oceanic food web.

A group of scientists, including one from the University of Arizona, has new findings suggesting Antarctica’s Southern Ocean — long known to play an integral role in climate change — may not be absorbing as much pollution as previously thought.

To reach their contradictory conclusion, the team used state-of-the-art sensors to collect more data on the Southern Ocean than ever before, including during the perilous winter months that previously made the research difficult if not impossible.The old belief was the ocean pulled about 13 percent of the world’s carbon dioxide — a greenhouse gas that contributes to climate change — out of the atmosphere, helping put the brakes on rising global temperatures.

Some oceanographers suspect that less CO2 is being absorbed because the westerlies — the winds that ring the southernmost continent — are tightening like a noose. As these powerful winds get more concentrated, they dig at the water, pushing it out and away.

Water from below rises to take its place, dragging up decaying muck made of carbon from deep in the ocean that can then either be released into the atmosphere in the form of CO2 or slow the rate that CO2 is absorbed by the water. Either way, it’s not good.

The Southern Ocean is far away, but “for Arizona, this is what matters,” said Joellen Russell, the University of Arizona oceanographer and co-author on the paper revealing these findings. “We don’t see the Southern Ocean, and yet it has reached out the icy hand.”

Oceans, rivers, lakes and vegetation can moderate extreme changes in temperature. Southern Arizona has no such buffers, leaving us vulnerable as average global temperatures march upward.

“Everybody asks, ‘Why are you at the UA?’” Russell said about studying the Southern Ocean from the desert at the University of Arizona. She said the research is important to Arizona and the university supports her work.

…….. scientists know less about the Southern Ocean than the rest of the world’s oceans. What they do know is mostly limited to surface CO2 levels in the summer, when it’s safer to take measurements by ships with researchers aboard. Shipboard sensors that directly measure CO2 are the accepted scientific standard in these types of studies.

Understanding CO2 levels within the air, land and sea and how it is exchanged between the three is necessary for making more accurate future climate predictions.

To fill the gap in knowledge, Russell and her team have deployed an array of cylindrical tanks, called floats, that collect data on carbon and more in the Southern Ocean year-round. Russell leads the modeling component of this project called Southern Ocean Carbon and Climate Observations and Modeling, or SOCCOM.

The floats drift 1,000 meters below the surface. Every 10 days, they plunge a thousand meters deeper, then bob up to the surface before returning to their original depth.

For three years, 35 floats equipped with state-of-the-art sensors the size of a coffee cup have been collecting data along the way and beaming it back to the researchers, like Russell in Tucson. Within hours, the data is freely available online.

They measure ocean acidity, or pH, and other metrics to understand the biogeochemistry of the elusive ocean, but not without controversy.

Making a splash

Alison Gray, an oceanographer at the University of Washington, is the lead author on the study. She said there are two reasons the study may contradict what has previously been thought of about the Southern Ocean: The lack of winter-time observations at the ocean by other researchers and the fact that ocean carbon levels might vary throughout the year.

Warming oceans melting Antarctic ice shelves could accelerate sea level rise, Guardian, John Abraham, 9 May 18, “……With global warming, both of the poles are warming quite quickly, and this warming is causing ice to melt in both regions. When we think of ice melting, we may think of it melting from above, as the ice is heated from the air, from sunlight, or from infrared energy from the atmosphere. But in truth, a lot of the melting comes from below. For instance, in the Antarctic, the ice shelves extend from the land out over the water. The bottom of the ice shelf is exposed to the ocean. If the ocean warms up, it can melt the underside of the shelf and cause it to thin or break off into the ocean.

A new study, recently published in Science Advances, looked at these issues. One of the goals of this study was to better understand whether and how the waters underneath the shelf are changing. They had to deal with the buoyancy of the waters. We know that the saltier and colder water is, the denser it is.

Around Antarctica, water at the ocean surface cools down and becomes saltier. These combined effects make the surface waters sink down to the sea floor. But as ice melt increases, fresh water flows into the ocean and interrupts this buoyancy effect. This “freshening” of the water can slow down or shut down the vertical mixing of the ocean. When this happens, the cold waters at the surface cannot sink. The deeper waters retain their heat and melt the ice from below.

The study incorporated measurements of both temperature and salinity (saltiness) at three locations near the Dalton Iceberg Tongue on the Sabrina Coast in East Antarctica. The measurements covered approximately an entire year and gave direct evidence of seasonal variations to the buoyancy of the waters. The researchers showed that a really important component to water-flow patterns were ‘polynyas.’ These are regions of open water that are surrounded by ice, typically by land ice on one side and sea ice on the other side.

When waters from the polynya are cold and salty, the waters sink downwards and form a cold curtain around the ice shelf. However, when the waters are not salty (because fresh water is flowing into the polynya), this protective curtain is disrupted and warm waters can intrude from outside, leading to more ice melt.
Based on this study, we may see increased ice loss in the future – sort of a feedback loop. That concerns us because it will mean more sea level rise (which is already accelerating), and more damage to coastal communities. I asked the lead author, Alesandro Silvano about this work:

Lead author Alesandro Silvano.

We found that freshwater from melting ice shelves is already enough to stop formation of cold and salty waters in some locations around Antarctica. This process causes warming and freshening of Antarctic waters. Ocean warming increases melting of the Antarctic Ice Sheet, causing sea level to rise. Freshening of Antarctic waters weakens the currents that trap heat and carbon dioxide in the ocean, affecting the global climate. In this way local changes in Antarctica can have global implications. Multiple sources of evidence exist now to show that these changes are happening. However, what will happen in Antarctica in the next decades and centuries remains unclear and needs to be understood.

1.This Month

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Changing climate change“2040” paints an optimistic picture of the future of the environment

The film focuses on technological and agricultural solutions that are already being implemented to help combat climate change, The Economist Feb 19th 2019

by C.G. | BERLIN ……….In “2040”, a documentary which premiered at the Berlinale, Mr Gameau seeks to wrest hope from the bleak reports of climate change. He was inspired by Project Drawdown, the first comprehensive plan to reverse global warming, and the film is intended as a “virtual letter to his four-year-old daughter to show her an alternative future”. “Many films,” Mr Gameau thinks, are too dystopian, and “paint a future that is really hard to engage and to connect with”. “2040” acknowledges that the Earth has set off down a hazardous path, but focuses on the work that is being done now to steer the right course. What, the film asks, could make 2040 a time worth living in?…. (subscribers only) https://www.economist.com/prospero/2019/02/19/2040-paints-an-optimistic-picture-of-the-future-of-the-environment